Process of producing alpha turpentine substitute from pine oil



Patented Aug. 12, 1930 UNET STATES IRVIN W. HUMPHREY, OF WEAR-TON, NEW JERSEY, ASSIGNOR T HERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A GOREORATION OF DELAWARE PROCESS OF PRODUCING A TUEPENTINE SUBSTITUTE FROM PINE OIL N0 Drawing. a

In the process for the extraction of rosin from resinous wood, there are also recovered substantial quantities of pine Oll and turpentine. Since turpentine is usually more valuable than pine oil, and since other operations carried on by the producer may require the use of larger quantities of turpentine, for solvent or other purposes, than is produced in the wood extracting'process, there may be no use, or but a limited use, for pine oil; or, due to temporary market conditions, there may be little demand for pine oil and a big demand for turpentine. I have discovered that pine oil may be converted into a substance that may be used, for most or all purposes, as a substitute for turpentine, and that has, in general, solvent properties superior to those of turpentine, although inferior to those of pine oil.

I have also discovered that my process may be so carried out as to produce a lim ited, but substantial, amount of other products, particularly borneol. which may have, as borneol has, a higher value per unit Weight than either pine oil, or the turpentine substitute, or turpentine.

My process comprises the dehydration of pine oil by means of clay or any argillaceous earth, preferably fullers earth, but I do not intend to confine myself to the use of any specific variety of argillaceous earth, except where specifically claimed.

Fullers earth appears to dehydrate by virtue of surface catalysis. It is possible to also effect dehydration by means of other substances which appear to function in a similar manner, namely, activated carbon and silicious materials such as kieselguhr.

The preferred method of executing my process involves the addition of fullers earth to the pine oil in the proportion of about two per cent, although the prportion added may vary from 0.5 to per cent, depending upon operating conditions and the character of the product which is desired. The hydrocarbons are slowly distilled ofi, preferably with the use of steam, through a fractionating column substantially as rapidly as they are formed. The chief constituent of pine oil is alphaterpineol, but considerable amounts of other Application filed July 20, 1926. Serial- No. 123,814.

oxygenated bodies, as well as a small proportion of terpene hydrocarbons, are also present. The distillate comprises mainly terpene hydrocarbons that are isomeric with pinene.

The main reaction may be representedthus:

C H OH +C H H O Dipentene is the most important hydrocarbon that is formed, but other terpene hydrocarbons, such as terpinene and 'limonene, are present. In addition, smaller amounts of paraffin and aromatic hydrocarbons may be formed in certain cases.

The specific gravity of the distillate at 15 C. is within the range .855 to .89, with between siXty-five to ninety-five per cent. distilling off below 185 C. I

The distillate has properties which make it more similar to turpentine than to pineoil.

The high boiling point residue amounts to from ten to thirty-five per cent of the original volume of pine oil'. It'has a specific gravity, at a temperature of 15 (1., within the approximate range, .94 to .99. g It consists essentially of various constituents of pine oil that have not been converted into the product above described, which I designate solven'ol. The residue is adapted for use as an ingredient of disinfectants. Some of the constituents of the residue are more as an equivalent for fullers' earth, as the use i of a halogen forms part of the subject-matter of another application filed by me of even date herewith; and, moreover, fullers earth has certainadvantagesover a halogen.

such as cheapness and the production of a crude distillate of lower-acidity, which-makes its use of distinct commercial advantage.

The borneol may be partially recovered from the residue by cooling with crystallization. Additional borneol may be recovered by fractionation of the residue, followed by cooling of the fractions.

The density, boiling range and percentage of the distillate may vary somewhat according to conditions. It may be desirable to redistill or to make several cuts in the distillate. It is usually preferred to give the distillate an alkali wash.

The amount of fullers earth used should be limited and the primary product should be removed from the fullers earth as soon as possible, in order to avoid subsequent polymerization. It is preferable to perform the reaction at 125225 C. (say 1? 0 C.) by distilling with steam. It is probable that the formation of a limited quantity of polymerized pine oil cannot be entirely avoided.

It will now be observed that by virtue of my invention not only is an efficient and economical method for the production of a turpentine substitute provided, but in addition borneol is produced in substantial proportion.

It will be understood that in claiming fullers earth I mean to include, as equivalents, the substitutes herein specifically mentioned, such as other argillaceous earths, siliceous earths, as kieselguhr, and activated carbon.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

1. The process of producing a turpentine substitute from pine oil which comprises adding fullers earth to the pine oil and distilling.

2. The process of producing a turpentine substitute from pine oil which comprises adding fullers earth to the pine oil and distilling with steam at a temperature between 125 C. and 225 C.

3. The process of securing a turpentine substitute and borneol from pine oil which comprises adding fullers earth to the pine oil, distilling off hydrocarbons comprising the turpentine substitute, and separating the borneol from the residue.

4. The process of producing a turpentine substitute from pine oil which comprises contacting pine oil at a temperature between 125 C. and 225 C. with fullers earth.

5. The process of treating pine oil which includes subjecting the pine oil to treatment with fullers earth, while distilling at a temperature below about 225 C. and separating borneol from the residue after distillation.

6. The step in the process of producing a turpentine substitute from pine oil which comprises subjecting pine oil to treatment with fullers earth in the presence of heat.

In testimony of which invention, I have hereunto set my hand at Kenvil, N. J on this 26th day of June, 1926.

IRVIN W. HUMPHREY. 

